As a member of the Liberal Party, Canadian Prime Minister Justin Trudeau promised to legalize cannabis during his 2015 campaign. But he had been contemplating the issue for far longer. In a 2013 interview with the Huffington Post, Trudeau admitted to sneaking a puff while a sitting member of Parliament. Then, last week, Trudeau released legislation that would make Canada the first industrialized nation to legalize marijuana. If it passes Parliament, which is widely expected, marijuana will be legally available across the vast nation by mid-2018.

While recreational marijuana for adult use is legal in eight U.S. states, and a growing tolerance of weed has cushioned the legalization announcement's impact, Canada's announcement is a major milestone for the legalization movement and big questions remain unanswered. Here, a what you need to know about recreational weed in Canada, and what that might mean for Americans.

How did Canada get here? Canada legalized medical marijuana in 2001. Since then, the industry has evolved in a staid way. Producers grow their crops in enormous warehouses and directly send product to patients by mail or courier service. Medical marijuana companies raise money by going public on the stock exchange, just like normal businesses. Dispensaries are still illegal in Canada, though they've been tolerated in some areas.

Cameras rolling, Richard Haines pitches his business: MDHerb, a website for medical marijuana patients to share their experiences with various products. He's looking for $150,000 in exchange for about 12 percent of the company. He says MDHerb is "a collaborative community" that lets patients "keep journal entries of what they're consuming and how cannabis is affecting their conditions."

Haines is auditioning for the third season of the online series The Marijuana Show. The setup is similar to the ABC reality show Shark Tank, which milks the face-off between hopeful entrepreneurs and calculating investors into compelling television. But The Marijuana Show only considers companies involved in the legal cannabis industry.

Haines, a clean-cut 31-year-old with a neat beard, is a colon cancer survivor and a Crohn's disease patient. He says he's spent a third of his life in the hospital. During his pitch, he pulls up his black "I'm a patient" t-shirt to show off the surgical scars on his "frankenbelly." Projected on the wall behind him is The Marijuana Show's logo: George Washington enjoying a joint.

As he pitches, Wendy Robbins and Karen Paull, who created, produce and host The Marijuana Show, cheer him on. "Speak from your heart, not from your head," Robbins says. She wants Haines to adopt a Twitter-ready pitch for MDHerb and suggests he sell it as the "Wikipedia for cannabis," though the analogy is inexact.

Early this month, the Drug Enforcement Administration announced that it would make a decision on whether to reclassify marijuana. Under the Controlled Substance Act, the federal government considers marijuana a Schedule I narcotic, meaning that it has high potential for abuse and no medical benefits, a position at odds with the 24 states that have legalized medical marijuana and the millions of casual users currently enjoying the occasional smoke. There's little dispute that the current classification of marijuana is absurd — other Schedule I drugs include heroin, LSD and MDMA; both cocaine and methamphetamine are considered less onerous Schedule II drugs. But there is much debate about what rescheduling might mean for the nascent legal pot industry.

Everyone agrees, that rescheduling marijuana would make it easier for scientists to research the plant. It would also vindicate the widely held belief that marijuana has important medicinal properties. And for the businesses generating over $5 billion worth of revenue on marijuana products each year, rescheduling would mean a major step towards finally legitimizing the industry.

But there is also cause for some concerns. The DEA has rejected petitions to reschedule marijuana three times. In each instance, the agency took years to make the decision. That kind of uncertainty is toxic for young businesses. In addition, rescheduling marijuana could unleash new federal oversight that would make life even more difficult for companies that already operate at the whim of the White House. The Obama administration has allowed the industry to operate in states where pot is legal, but the next administration could take a different approach.

In polls, more than 80 percent of voters in Ohio favor medical marijuana, and a small majority want to see it legalized for all adults. These numbers are roughly in line with national sentiment.

Tuesday's lopsided vote reflects disgust with how the Ohio market would have been structured. Ten companies each donated $2 million to support the legalization campaign, known as Issue 3, and if it had passed the ten groups would have essentially been granted exclusive and indefinite permission to grow commercial marijuana in the state, a business estimated at $1 billion annually.

The pay-to-play arrangement was so off-putting that national pro-legalization groups like the Drug Policy Alliance and the Marijuana Policy Project declined to endorse it, despite the real and symbolic value of legal pot in the big Midwestern bellweather state. "The 19th-century robber barons couldn't have dreamed up a more perfect plan," the Cleveland Plain Dealer editorialized.